• Journal of Microbiology and Biotechnology
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• v.18 no.12
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• pp.1997-2003
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• 2008

Cordyceps militaris is well known as a traditional medicinal mushroom and has been shown to exhibit immunostimulatory and anticancer activities. In this study, we investigated the apoptosis induced by an aqueous extract of C. militaris (AECM) via the activation of caspases and altered mitochondrial membrane permeability in human breast cancer MDA-MB-231 cells. Exposure to AECM induced apoptosis, as demonstrated by a quantitative analysis of nuclear morphological change and a flow cytometric analysis. AECM increased hyperpolarization of mitochondrial membrane potential and promoted the activation of caspases. Both the cytotoxic effect and apoptotic characteristics induced by AECM treatment were significantly inhibited by z-DEVD-fmk, a caspase-3 inhibitor, which demonstrates the important role of caspase-3 in the observed cytotoxic effect. AECM-induced apoptosis was associated with the inhibition of Akt activation in a time-dependent manner, and pretreatment with LY294002, a PI3K/Akt inhibitor, significantly increased AECM-induced apoptosis. The results indicated that AECM-induced apoptosis may relate to the activation of caspase-3 and mitochondria dysfunctions that correlate with the inactivation of Akt.

• Journal of Food Hygiene and Safety
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• v.14 no.1
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• pp.60-66
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• 1999

Diethylnitrosamine (DEN) is known as a potential hepatic carcinogen by single administration. This study was designed to measure the effects of DEN-induced cell damage on the triglyceride and cholesterol concentration in the liver, excluding dietary effects. Fertilized chicken eggs, 10 days before hatching, were randomly divided into three groups (n=20) and each egg was injected 10 ${mu}ell$ of corn oil (vehicle control), 5 $\mu\textrm{g}$ of DEN/10 ${mu}ell$ of DEN/10 ${mu}ell$ into yolk via air sac. After 48 hr and 96 hr incubation, the damage of the chick-embryo liver cell was investigated by electron microscopy and by measuring the concentration of lipid components (total cholesterol, free cholesterol, phospholipid and triglyceride). For eggs administered 10 $\mu\textrm{g}$ of DEN and incuvated 96 hr, in hepatocyte, the nucleus membrane was roughed, the size of nucleolus was apparently increased and euchromatin was accumulated. Mitochondria were condensed and cristae, located mitochondiral inner membrane, were obscured. Additionally, the leaves of triglyceride and cholesterol classes were significantly increased depend on the amount treated with 10 $\mu\textrm{g}$ DEN at 96 hr, but phospholipids component of cell membrane, were decreased with significance. As a conclusion, carcinogen induced hepatic lesion was correlated with the changes in lipid component of liver.

• Journal of Physiology & Pathology in Korean Medicine
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• v.19 no.4
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• pp.965-972
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• 2005

To investigate the effects of Trichosanthes semen extract on the growth and apoptosis of human uterine cervical carcinoma cells. Effects of Trichosanthes semen extract on the growth of ME-180 cells were assayed by MTT assay. Apoptosis induced by Trichosanthes semen extract was detected by fluorescent microscopy, DNA fragmentation analysis and flow cytometry. Caspase-3 and caspase-8 activities were assayed. Trichosanthes semen extract induced ME-180 cells to die in a dose- and time-dependent manner. ME-180 cells treated with Trichosanthes semen extract exhibited typical characteristics of apoptosis. The population of Sub-G1 cells increased significantly, and the cells represented the reduced size, condensed chromatin and apoptotic bodies. They showed the decreased mitochondrial membrane potential and increased activities of caspase-3 and caspase-8. The results suggest that Trichosanthes semen extract induced ME-180 cell apoptosis and the activation of caspase and mitochondrial pathway were involved in the process of Trichosanthes semen extract-induced apoptosis.

• Clinical and Experimental Reproductive Medicine
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• v.20 no.1
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• pp.19-29
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• 1993

Plasminogen activator (PA)-plasmin system in follicular fluid is involved in the process leading to follicular rupture at ovulation. It is well known that PA is closely associated with cellular differentiation and tissue remodeling on evidences from the study of normal and malignant tissues. This study was designed to ascertain a potential role of PA in the ovarian folliculogenesis. Immature Sprague-Dawley rats were injected with pregnant mare serum gonadotropin, followed by injection of serine protease inhibitor (SPI; mixture of 1 mol/L benzamidine and 1 mol/L amino-caproic acid) into the unilateral ovarian bursa. In the control study, mechanical effect of bursal injection and contralateral ovarian effect SPI were ruled out. Total antral follicular areas relative to total ovarian cross-sectional areas was siginificantly lower in SPI-injected ovary than in saline-injected ovary. SPI injection decreased the relative antral follicular area by 33 % respectively. Electron microscopic finding of granulosa cell in the atretic follicle showed the presence of pyknotic nucleus, blurring of neucleolemma, degeneration of mitochondria and dilation of endoplasmic reticulum. After induction of ovulation with hCG, the number of oocytes released was significantly decreased in SPI-injected oviduct than in saline-injected oviduct. From above results, author discussed that PA may play a role not only in ovulation but also in some processes of folliculogenesis.

• Molecules and Cells
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• v.26 no.1
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• pp.12-17
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• 2008

The TrkA tyrosine kinase is activated by autophosphorylation in response to NGF, and plays an important role in cell survival, differentiation, and apoptosis. To investigate its role in cell fate determination, we produced stable TrkA-inducible SK-N-MC and U2OS cell lines using the Tet-On system. Interestingly, TrkA overexpression induced substantial cell death even in the absence of NGF, by stimulating ERK phosphorylation and caspase-7 activation leading to PARP cleavage. TrkA-mediated cell death was shown by the annexin-V binding assay to be, at least in part, apoptotic in both SK-N-MC and U2OS cells. Furthermore, the truncated form (p18) of Bax accumulated in the TrkA-induced cells, suggesting that TrkA induces mitochondria-mediated apoptosis. NGF treatment augmented the cell death induced by TrkA overexpression. This TrkA-induced cell death was blocked by the tyrosine kinase inhibitors, K-252a and GW441756. Moreover, TrkA overexpression inhibited long-term proliferation of both the neuronal SK-N-MC cells and the non-neuronal U2OS cells, suggesting a potential role of TrkA as a tumor suppressor.

• Molecules and Cells
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• v.37 no.6
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• pp.441-448
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• 2014

Inflammasomes are specialized signaling platforms critical for the regulation of innate immune and inflammatory responses. Various NLR family members (i.e., NLRP1, NLRP3, and IPAF) as well as the PYHIN family member AIM2 can form inflammasome complexes. These multiprotein complexes activate inflammatory caspases (i.e., caspase-1) which in turn catalyze the maturation of select pro-inflammatory cytokines, including interleukin (IL)-$1{\beta}$ and IL-18. Activation of the NLRP3 inflammasome typically requires two initiating signals. Toll-like receptor (TLR) and NOD-like receptor (NLR) agonists activate the transcription of pro-inflammatory cytokine genes through an NF-${\kappa}B$-dependent priming signal. Following exposure to extracellular ATP, stimulation of the P2X purinoreceptor-7 ($P2X_7R$), which results in $K^+$ efflux, is required as a second signal for NLRP3 inflammasome formation. Alternative models for NLRP3 activation involve lysosomal destabilization and phagocytic NADPH oxidase and /or mitochondria-dependent reactive oxygen species (ROS) production. In this review we examine regulatory mechanisms that activate the NLRP3 inflammasome pathway. Furthermore, we discuss the potential roles of NLRP3 in metabolic and cognitive diseases, including obesity, type 2 diabetes mellitus, Alzheimer's disease, and major depressive disorder. Novel therapeutics involving inflammasome activation may result in possible clinical applications in the near future.

• The Journal of Korean Medicine
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• v.30 no.1
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• pp.64-75
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• 2009

Objective: This study was designed to investigate the effect of Samultang (SMT) under hippocampus cells ischemia both in vitro and in vivo. Methods: In the in vitro study, HT22 cells, predominantly detected in the cytoplasm, which coincides with the location of the mitochondria, were used as indicators. In the in vivo study, permanent middle cerebral artery occlusion (MCAO) was induced on rats. SMT was given orally 2 h before induction of permanent focal brain ischemic injury. Result: In the in vitro study, SMT had protective effects in glutamate-induced cytotoxicity, which was revealed as apoptosis characterized by chromatic condensation and the loss of mitochondrial membrane potential in HT22 cells. In the in vivo study, TTC (2,3,5-triphenyltetrazolium chloride) staining showed a marked ischemic injury in blood supply territory of the middle cerebral artery (MCA) such as the cerebral cortex and striatum. However, treatment with SMT significantly reduced infarcted volume. SMT increased marked survival of HT22 cells against glutamate-induced cytotoxicity in MTT assay. Conclusion: These results suggest that water extract of SMT provides neuroprotection against ischemic or oxidative injury by inhibition of apoptotic cell death.

• Archives of Pharmacal Research
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• v.25 no.1
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• pp.93-101
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• 2002

The extract of European mistletoe ( Viscum album, L) has been used in adjuvant chemotherapy of cancer and mistletoe lectins are considered to be major active components. The present work was performed to investigate the effects of Korean mistletoe lectin (Viscum album L. coleratum agglutinin, VCA) on proliferation and apoptosis of human hepatoma cells as well as the underlying mechamisns for these effects. We showed that VCA induced atoptosis in both SK-Hep-1 and Hep 3B (p53-negative) cells through p53- and p21 -independent pathways. VCA induced apoptosis by down-regulation of Bcl-2 and by up-regulation of Bax functioning upstream of caspase-3 in both cell lines. In addition, we observed down-regulation of telomerase activity in both VCA-treated cells. Our results provide direct evidence of the anti-tumor potential of this biological response which comes from inhibition of telomerase and consequent inducing apoptosis. VCA-induced apoptosis is regulated by mitochondria controlled pathway independently of p53. These findings are important for the therapy with preparation of mistletoe because they show that telomerase-dependent mechanism can be targeted by VCA in human hepatocarcinoma. Taken together, our results suggest that the VCA, considered as a telomerase-inhibitor, can be envisaged as a candidate for enhancing sensitivity of conventional anticancer drugs.

• International Journal of Oral Biology
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• v.42 no.2
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• pp.55-61
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• 2017

Recent studies indicate that mitochondria are an important source of reactive oxygen species (ROS) in the spinal dorsal horn. In our previous study, application of malate, a mitochondrial electron transport complex I substrate, induced a membrane depolarization, which was inhibited by pretreatment with ROS scavengers. In the present study, we used patch clamp recording in the substantia geletinosa (SG) neurons of spinal slices, to investigate the cellular mechanism of mitochondrial ROS on neuronal excitability. DNQX (an AMPA receptor antagonist) and AP5 (an NMDA receptor antagonist) decreased the malate-induced depolarization. In an external calcium free solution and addition of tetrodotoxin (TTX) for blockade of synaptic transmission, the malate-induced depolarization remained unchanged. In the presence of DNQX, AP5 and AP3 (a group I metabotropic glutamate receptor (mGluR) antagonist), glutamate depolarized the membrane potential, which was suppressed by PBN. However, oligomycin (a mitochondrial ATP synthase inhibitor) or PPADS (a P2 receptor inhibitor) did not affect the substrates-induced depolarization. These results suggest that mitochondrial substrate-induced ROS in SG neuron directly acts on the postsynaptic neuron, therefore increasing the ion influx via glutamate receptors.

• Biomolecules & Therapeutics
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• v.19 no.4
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• pp.445-450
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• 2011

Preciously, we demonstrated that a novel NHE-1 inhibitor, KR-33028 attenuated cortical neuronal apoptosis induced by glutamate. In the present study, we investigated the signaling mechanism of neuroprotective effect of KR-33028 against glutamate-induced neuronal apoptosis, especially focusing on mitochondrial death pathway. Our data showed that glutamate induces a biphasic rise in mitochondrial $Ca^{2+}$ and that KR-33028 significantly prevents the second phase increase, but not the first phase increase in mitochondrial $Ca^{2+}$. Furthermore, KR-33028 restored the ${\Delta}{\Psi}_m$ dissipation and cytochrome c release into cytoplasm induced by glutamate in a concentration-dependent manner. The inhibition of mitochondrial $Ca^{2+}$ overload by ruthenium red also inhibited glutamate-induced apoptotic cell death, mitochondrial membrane potential, ${\Delta}{\Psi}_m$ dissipation and cytochrome c release. These data suggest that inhibition of mitochondrial $Ca^{2+}$ overload is likely to be attributable to anti-apoptotic effect of KR-33028. Taken together, our results suggest that anti-apoptotic effects of NHE-1 inhibitor, KR-33028 may be mediated through maintenance of mitochondrial function.